100 resultados para mitochondrial control region and cytochrome b
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The therapeutic efficacy of amphotericin B and voriconazole alone and in combination with one another were evaluated in immunodeficient mice (BALB/c-SCID) infected with a fluconazole-resistant strain of Cryptococcus neoformans var. grubii. The animals were infected intravenously with 3 x 10(5) cells and intraperitoneally treated with amphotericin B (1.5 mg/kg/day) in combination with voriconazole (40 mg/kg/days). Treatment began 1 day after inoculation and continued for 7 and 15 days post-inoculation. The treatments were evaluated by survival curves and yeast quantification (CFUs) in brain and lung tissues. Treatments for 15 days significantly promoted the survival of the animals compared to the control groups. Our results indicated that amphotericin B was effective in assuring longest-term survival of infected animals, but these animals still harbored the highest CFU of C. neoformans in lungs and brain at the end of the experiment. Voriconazole was not as effective alone, but in combination with amphotericin B, it prolonged survival for the second-longest time period and provided the lowest colonization of target organs by the fungus. None of the treatments were effective in complete eradication of the fungus in mice lungs and brain at the end of the experiment.
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Nuclear (p,alpha) reactions destroying the so-called ""light-elements"" lithium, beryllium and boron have been largely studied in the past mainly because their role in understanding some astrophysical phenomena, i.e. mixing-phenomena occurring in young F-G stars [1]. Such mechanisms transport the surface material down to the region close to the nuclear destruction zone, where typical temperatures of the order of similar to 10(6) K are reached. The corresponding Gamow energy E(0)=1.22 (Z(x)(2)Z(X)(2)T(6)(2))(1/3) [2] is about similar to 10 keV if one considers the ""boron-case"" and replaces in the previous formula Z(x) = 1, Z(X) = 5 and T(6) = 5. Direct measurements of the two (11)B(p,alpha(0))(8)Be and (10)B(p,alpha)(7)Be reactions in correspondence of this energy region are difficult to perform mainly because the combined effects of Coulomb barrier penetrability and electron screening [3]. The indirect method of the Trojan Horse (THM) [4-6] allows one to extract the two-body reaction cross section of interest for astrophysics without the extrapolation-procedures. Due to the THM formalism, the extracted indirect data have to be normalized to the available direct ones at higher energies thus implying that the method is a complementary tool in solving some still open questions for both nuclear and astrophysical issues [7-12].
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Cerradomy's is a monophyletic genus that includes four known species, Cerradomys subflavus, C maracajuensis, C. marinhus, and C. scotti, distributed throughout the open vegetation belt across South America, from northeastern Brazil to southeastern Bolivia, and from eastern to northwestern Paraguay. We revised the status of the species currently assigned to this genus by analyzing skins, skulls, karyotypes, and cytochrome b DNA sequences. We also described two novel species, one distributed in the Brazilian states of Minas Gerais, Bahia, and Sergipe, and the other in the states of Paraiba, Pernambuco, Piaui, Ceara, and Maranhao. Molecular analysis suggested the following phylogenetics arrangement: (((C. subflavus-C. sp.n.2) C. sp.n.1) C scotti)(C. marinhus-C. maracajuensis)). Apparently, both novel species inhabit the Caatinga domain and penetrated the coastal Atlantic rainforest, differing from the remaining congeneric species that are typical open-area inhabitants.
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Background: HBV-HIV co-infection is associated with an increased liver-related morbidity and mortality. However, little is known about the natural history of chronic hepatitis B in HIV-infected individuals under highly active antiretroviral therapy (HAART) receiving at least one of the two drugs that also affect HBV (TDF and LAM). Information about HBeAg status and HBV viremia in HIV/HBV co-infected patients is scarce. The objective of this study was to search for clinical and virological variables associated with HBeAg status and HBV viremia in patients of an HIV/HBV co-infected cohort. Methods: A retrospective cross-sectional study was performed, of HBsAg-positive HIV-infected patients in treatment between 1994 and 2007 in two AIDS outpatient clinics located in the Sao Paulo metropolitan area, Brazil. The baseline data were age, sex, CD4 T+ cell count, ALT level, HIV and HBV viral load, HBV genotype, and duration of antiretroviral use. The variables associated to HBeAg status and HBV viremia were assessed using logistic regression. Results: A total of 86 HBsAg patients were included in the study. Of these, 48 (56%) were using combination therapy that included lamivudine (LAM) and tenofovir (TDF), 31 (36%) were using LAM monotherapy, and 7 patients had no previous use of either one. Duration of use of TDF and LAM varied from 4 to 21 and 7 to 144 months, respectively. A total of 42 (48. 9%) patients were HBeAg positive and 44 (51. 1%) were HBeAg negative. The multivariate analysis revealed that the use of TDF for longer than 12 months was associated with undetectable HBV DNA viral load (serum HBV DNA level < 60 UI/ml) (p = 0. 047). HBeAg positivity was associated with HBV DNA > 60 UI/ml (p = 0. 001) and ALT levels above normality (p = 0. 038). Conclusion: Prolonged use of TDF containing HAART is associated with undetectable HBV DNA viral load. HBeAg positivity is associated with HBV viremia and increased ALT levels.
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The present study evaluated the effect of aflatoxin B(1) (AFB(1)) and fumonisin B(1) (FB(1)) either alone, or in association, on rat primary hepatocyte cultures. Cell viability was assessed by flow cytometry after propidium iodine intercalation. DNA fragmentation and apoptosis were assessed by agarose gel electrophoresis and acridine orange and ethidium bromide staining. At the concentrations of AFB(1) and FB(1) used, the toxins did not decrease cell viability, but did induce apoptosis in a concentration and time-dependent manner.
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In this work we review recent findings that explain how mitochondrial bioenergetic functions and redox state respond to a hyperlipidemic in vivo environment and may contribute to the maintenance of a normal metabolic phenotype. The experimental model utilized to evidence these adaptive mechanisms is especially useful for these studies since it exhibits genetic hypertriglyceridemia and avoids complications introduced by high fat diets. Liver from hypertrigliceridemic (HTG) mice have a greater content of glycerolipids together with increased mitochondrial free fatty acid oxidation. HTG liver mitochondria have a higher resting respiration rate but normal oxidative phosphorylation efficiency. This is achieved by higher activity of the mitochondrial potassium channel sensitive to ATP (mitoK(ATP)). The mild uncoupling mediated by mitoK(ATP) accelerates respiration rates and reduces reactive oxygen species generation. Although this response is not sufficient to inhibit lipid induced extra-mitochondrial oxidative stress in whole liver cells it avoids amplification of this redox imbalance. Furthermore, higher mitoK(ATP) activity increases liver, brain and whole body metabolic rates. These mitochondrial adaptations may explain why these HTG mice do not develop insulin resistance and obesity even under a severe hyperlipidemic state. On the contrary, when long term high fat diets are employed, insulin resistance, fatty liver and obesity develop and mitochondrial adaptations are inefficient to counteract energy and redox imbalances.
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An 18-year-old boy with refractory epilepsy and aggressiveness associated to a hypothalamic hamartoma was submitted to a stereotactically guided lesion by thermocoagulation. The target was based on magnetic resonance (MR) images merged with computed tomography scan images taken on the day of surgery while patient was on a stereotactic frame. In order to reveal structures not discernible in MR images, the Schaltenbrand digital brain atlas was merged onto the patient`s images. Target and trajectory of the depth electrode were chosen based on three-dimensional imaging reconstructions. A surgical plan was devised to disconnect the hypothalamic hamartoma from the hypothalamus, medial forebrain bundle, fasciculus princeps, and dorsal longitudinal fasciculus. Our target was placed at the inferior portion of the posterolateral component of the hamartoma, bordering the normal hypothalamus. The patient evolved with marked lessening of aggressiveness. Seizure frequency was reduced from several seizures per day to less than one tonic-clonic seizure during sleep per month and only two episodes suggestive of partial complex seizures during daytime. These results have remained consistent over a 24-month postoperative follow-up. Functional neuroanatomy of hypothalamic connections involved in seizure propagation and aggressive behavior was reviewed.
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Polymorphisms in the methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR) and cystathionine P-synthase (CBS) genes, involved in the intracellular metabolism of homocysteine (Hcy), can result in hyperhomocysteinemia. The objective of this study was to evaluate prevalence estimates of CBS T833C, G919A and the insertion of 68-bp (844ins68) polymorphisms and their correlation with Hcy, folate and 131, in 220 children previously genotyped for MTHFR C677T, A1298C, and MTRR A66G. The prevalence of heterozygote children for 844ins68 was 19.5%. The T833C CBS mutation was identified in association with 844ins68 in all the carriers of the insertion. Genotyping for CBS G919A mutation showed that all the children presented the GG genotype. Analysis of Hcy, B(12) and folate, according to the combination of the different genotypes of the C677T and A1298C MTHFR, A66G MTRR, and 844ins68 CBS showed that the 677TT/1298AA/68WW genotype is associated with an increase in Hcy, when compared to the 677CC/1298AC/68WW (P = 0.033) and the 677CT/1298AA/68WW genotypes (P = 0.034). Since B(12) and folate were not different between these groups, a genetic interaction between diverse polymorphisms probably influences Hcy. Our results emphasize the role of genetic interactions in Hcy levels. (C) 2008 Wiley-Liss, Inc.
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OBJECTIVE: We present observations of the anatomy of the sylvian fissure region and their clinical application in neuroimaging, microsurgery for middle cerebral artery aneurysms and insular lesions, frontobasal resections, and epilepsy Surgery. METHODS: Sixty adult cadaveric hemispheres and 12 adult cadaveric heads were studied after perfusion of the arteries and veins with colored latex. The anatomic information was applied in more than 200 microsurgeries in and around the sylvian fissure region in the past 15 years. RESULTS: The sylvian fissure extends from the basal to the lateral surface of the brain and presents 2 compartments on each surface, I superficial (temporal stem and its ramii) and 1 deep (anterior and lateral operculoinsular compartments). The temporal operculum is in opposition to the frontal and parietal opercula (planum polare versus inferior frontal and precentral gyri, Heschl`s versus postcentral gyri, planum temporale versus supramarginal gyrus). The inferior frontal, precentral, and postcentral gyri cover the anterior, middle, and posterior thirds of the lateral surface of the insula, respectively. The pars triangularis covers the apex of the insula, located immediately distal to the genu of the middle cerebral artery. The clinical application of the anatomic information presented in this article is in angiography, middle cerebral artery aneurysm surgery, insular resection, frontobasal resection, and amygdalohippocampectomy, and hemispherotomy. CONCLUSION: The anatomic relationships of the sylvian fissure region can be helpful in preoperative planning and can serve as reliable intraoperative navigation landmarks in microsurgery involving that region.
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Endothelin may contribute to the development of inflammatory events such as leukocyte recruitment and nociception. Herein, we investigated whether endothelin-mediated mechanical hypernociception (decreased nociceptive threshold, evaluated by electronic pressure-meter) and neutrophil migration (myeloperoxidase activity) are inter-dependent in antigen challenge-induced Th1-driven hind-paw inflammation. In antigen challenge-induced inflammation, endothelin (ET) ET(A) and ET(B) receptor antagonism inhibited both hypernociception and neutrophil migration. Interestingly, ET-1 peptide-induced hypernociception was not altered by inhibiting neutrophil migration or endothelin ET(B) receptor antagonism, but rather by endothelin ET(A) receptor antagonism. Furthermore, endothelin ET(A), but not ET(B), receptor antagonism inhibited antigen-induced PGE(2) production, whereas either selective or combined blockade of endothelin ET(A) and/or ET(B) receptors reduced hypernociception and neutrophil recruitment caused by antigen challenge. Concluding, this study advances knowledge into the role for endothelin in inflammatory mechanisms and further supports the potential of endothelin receptor antagonists in controlling inflammation.
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Acestrorhynchus is the sole genus of the family Acestrorhynchidae which includes 14 species currently recognized as valid. Species of Acestrorhynchus comprise small-to-medium sized piscivorous fishes and have been traditionally grouped on the basis of well-defined color patterns. A recent phylogeny, based on morphological characters, could not resolve the phylogenetic affinities of A. heterolepis and the relationships among the species of the clade formed by A. abbreviatus, A. altus, A. falcatus, A. lacustris, and A. pantaneiro. The simultaneous analysis of two mitochondrial genes (16S and ATP synthase subunits 6 and 8) and one nuclear intron (S7) was able to resolve the latter clade, but the position of A. heterolepis remained unresolved. The combination of the molecular and morphological data sets in a total evidence analysis resulted in a well-resolved hypothesis regarding the phylogenetic relationships of Acestrorhynchus species. (C) 2009 Elsevier Inc. All rights reserved.
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Phylogenetic analyses of chloroplast DNA sequences, morphology, and combined data have provided consistent support for many of the major branches within the angiosperm, clade Dipsacales. Here we use sequences from three mitochondrial loci to test the existing broad scale phylogeny and in an attempt to resolve several relationships that have remained uncertain. Parsimony, maximum likelihood, and Bayesian analyses of a combined mitochondrial data set recover trees broadly consistent with previous studies, although resolution and support are lower than in the largest chloroplast analyses. Combining chloroplast and mitochondrial data results in a generally well-resolved and very strongly supported topology but the previously recognized problem areas remain. To investigate why these relationships have been difficult to resolve we conducted a series of experiments using different data partitions and heterogeneous substitution models. Usually more complex modeling schemes are favored regardless of the partitions recognized but model choice had little effect on topology or support values. In contrast there are consistent but weakly supported differences in the topologies recovered from coding and non-coding matrices. These conflicts directly correspond to relationships that were poorly resolved in analyses of the full combined chloroplast-mitochondrial data set. We suggest incongruent signal has contributed to our inability to confidently resolve these problem areas. (c) 2007 Elsevier Inc. All rights reserved.
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The type I and type II heat-labile enterotoxins (LT-I and LT-II) are strong mucosal adjuvants when they are coadministered with soluble antigens. Nonetheless, data on the parenteral adjuvant activities of LT-II are still limited. Particularly, no previous study has evaluated the adjuvant effects and induced inflammatory reactions of LT-II holotoxins or their B pentameric subunits after delivery via the intradermal (i.d.) route to mice. In the present report, the adjuvant and local skin inflammatory effects of LT-IIa and its B subunit pentamer (LT-IIaB(5)) were determined. When coadministered with ovalbumin (OVA), LT-IIa and, to a lesser extent, LT-IIaB(5) exhibited serum IgG adjuvant effects. In addition, LT-IIa but not LT-IIaB(5) induced T cell-specific anti-OVA responses, particularly in respect to induction of antigen-specific cytotoxic CD8(+) T cell responses. LT-IIa and LT-IIaB(5) induced differential tissue permeability and local inflammatory reactions after i.d. injection. Of particular interest was the reduced or complete lack of local reactions, such as edema and tissue induration, in mice i.d. inoculated with LT-IIa and LT-IIaB(5), respectively, compared with mice immunized with LT-I. In conclusion, the present results show that LT-IIa and, to a lesser extent, LT-IIaB(5) exert adjuvant effects when they are delivered via the i.d. route. In addition, the low inflammatory effects of LT-IIa and LT-IIaB(5) in comparison to those of LT-I support the usefulness of LT-IIa and LT-IIaB(5) as parenterally delivered vaccine adjuvants.
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Resistance of Leishmania parasites to specific chemotherapy has become a well-documented problem in the Indian subcontinent in recent years but only a few studies have focused on the susceptibility of American Leishmania isolates. Our susceptibility assays to meglumine antimoniate were performed against intracellular amastigotes after standardizing an in vitro model of macrophage infection appropriate for Leishmania (Viannia) braziliensis isolates. For the determination of promastigote susceptibility to amphotericin B, we developed a simplified MTT-test. The sensitivity in vitro to meglumine antimoniate and amphotericin B of 13 isolates obtained from Brazilian patients was determined. L. (V.) braziliensis isolates were more susceptible to meglumine antimoniate than Leishmania (Leishmania) amazonensis. EC(50), EC(90) and activity indexes (calculated over the sensitivity of reference strains), suggested that all isolates tested were susceptible in vitro to meglumine antimoniate, and did not show association with the clinical outcomes. Isolates were also uniformly susceptible in vitro to amphotericin B.
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We previously demonstrated that Bis[(2-oxindol-3-ylimino)-2-(2-aminoethyl) pyridine-N, N`] copper(II) [Cu(isaepy)(2)] was an efficient inducer of the apoptotic mitochondrial pathway. Here, we deeply dissect the mechanisms underlying the ability of Cu(isaepy)(2) to cause mitochondriotoxicity. In particular, we demonstrate that Cu(isaepy)(2) increases NADH-dependent oxygen consumption of isolated mitochondria and that this phenomenon is associated with oxy-radical production and insensitive to adenosine diphosphate. These data indicate that Cu(isaepy)(2) behaves as an uncoupler and this property is also confirmed in cell systems. Particularly, SH-SY5Y cells show: (i) an early loss of mitochondrial transmembrane potential; (ii) a decrease in the expression levels of respiratory complex components and (iii) a significant adenosine triphosphate (ATP) decrement. The causative energetic impairment mediated by Cu(isaepy)(2) in apoptosis is confirmed by experiments carried out with rho(0) cells, or by glucose supplementation, where cell death is significantly inhibited. Moreover, gastric and cervix carcinoma AGS and HeLa cells, which rely most of their ATP production on oxidative phosphorylation, show a marked sensitivity toward Cu(isaepy)(2). Adenosine monophosphate-activated protein kinase (AMPK), which is activated by events increasing the adenosine monophosphate: ATP ratio, is deeply involved in the apoptotic process because the overexpression of its dominant/negative form completely abolishes cell death. Upon glucose supplementation, AMPK is not activated, confirming its role as fuel-sensing enzyme that positively responds to Cu(isaepy)(2)-mediated energetic impairment by committing cells to apoptosis. Overall, data obtained indicate that Cu(isaepy)(2) behaves as delocalized lipophilic cation and induces mitochondrial-sited reactive oxygen species production. This event results in mitochondrial dysfunction and ATP decrease, which in turn triggers AMPK-dependent apoptosis.